Planning a house extension in 2025? You’re not alone. With property prices soaring and the housing market remaining competitive, more homeowners are choosing to extend rather than move. But what should you expect to pay for that extra space you’ve been dreaming of?

The short answer: house extension costs in the UK average around £40,000, but this figure can vary dramatically based on your specific requirements, location, and the type of extension you’re planning. Let’s break down everything you need to know about extension costs in 2025.